This revised version of our TMRC P50 application, re-titled "Emerging Helminthiasis in China: Genetic Diversity, Transmission Dynamics, and the Impact of Environmental Changes", has been prepared to reflect and incorporate the recommendations of the year 2000 Study Section. In brief, this application contains four discrete yet synergistically interrelated projects. These four projects are entitled: 1. Schistosoma japonicum: Genomics, post-genomics and genetic diversity; 2. Ecogenetics of Schistosoma japonicum transmission in China; 3. Environmental change impacting on control and transmission of Schistosoma japonicum, and 4. Population genetics and transmission patterns of hookworms in China. In addition, it has three cores: Core; Repository for Bio-Informatics, Voucher Specimens, and the RS-GIS Database; and Visiting Scientist Opportunity. Our year 2000 application included five projects and four cores. Three of the 5 projects have been retained, although these projects have been appropriately revised and re-titled. These are projects 4-7 above. We have removed two projects that were included in the year 2000 version. The first of these dealt with Paragonimus spp. It was not given a priority score. The second dealt with transmission of Echinococcus granulosus in western China. We have decided not to pursue this issue here because we felt that we could not, with our current personnel and material, re-frame and re-build the project to a level that would unfalteringly attract an outstanding score. By contrast, we have substituted a new project 6 in place of the two that were removed. This project, "Environmental change impacting on control and transmission of Schistosoma japonicum" is included because it addresses the key issues of the roles of bovines in transmission of human Schistosoma japonicum, and the relationships of different transmission modes of S. japonicum infection. It continues some of the ongoing work in Jiangxi Province that is currently supported by the ongoing grant; the work is at a crucial stage and requires another 2 years to complete. Furthermore, the inclusion of a significant mathematical modeling component of project 6 follows on from some preliminary work that commenced as part of the previous P50 grant and continues in the current program. This modeling aspect is at an exciting stage and it will allow us to predict the impact of the Three Gorges Dam (TGD) on schistosomiasis in southern China and to evaluate the effect of the dam on the cost effectiveness of anti-schistosomiasis control programs that will need to be orchestrated following closure of the dam. The concluding workshop at a recent International Symposium on Schistosomiasis held in China (July 2001, Shanghai) emphasized the timeliness and importance of undertaking studies along the lines described in this project so as to determine the impact of the TGD on human schistosomiasis transmission in southern China. Our group is in a unique position to do this. Finally, project 6 provides direct links and synergies with the other two schistosometargeted projects, project numbers 4 and 5, above; links that the Study Section encouraged us to pursue. Specific point-by-point responses to the Study Section comments and recommendations are detailed at the beginning of the three relevant project applications (projects 4, 5, and 7).